Marlon Brando's son has refused to answer questions in the wrongful death civil case against actor Robert Blake over the killing of Mr Blake's wife.
Mr Brando had a relationship with the victim before she married Mr Blake
Christian Brando, 46, invoked the Fifth Amendment for some questions at the court in Burbank, California, to avoid possible self-incrimination.
Mr Brando had a relationship with Bonny Lee Bakley before she married Mr Blake.
A jury in March cleared Mr Blake, 72, of murdering Ms Bakley, 44, in 2001. Her family is bringing a civil case.
Ms Bakley was killed outside a restaurant in Los Angeles in May 2001.
A US judge last year ruled there was no evidence linking Mr Brando with the murder.
Mr Blake, star of 1970s US TV drama Baretta, claims that at the time of the shooting he was in the restaurant picking up a handgun he had left behind.
In court on Tuesday, Mr Brando gave his name and birth date, and identified his voice on tape recordings of telephone conversations with Ms Bakley.
But he refused to give details of his relationship with her.
Mr Blake was cleared of his wife's murder in March
He also declined to answer questions about whether he hired someone to kill her, or if she told him she feared Mr Blake was going to kill her.